Reading the device tag or descriptor in a HART loop provides what type of information?

• A. Device's identity, description, and capabilities
• B. The device's measurement value
• C. The loop current only
• D. The device's power consumption

Answer: (A)

In a HART loop, the device tag or descriptor provides metadata about the device—who made it, what the device is (identity and description), and what it can do or what data it supports (capabilities). This information is used for identification, setup, and asset management, not for the live measurement itself. The actual measurement value comes from separate reads, and the loop current is the physical signal on the 4-20 mA loop, not metadata. Power consumption isn’t typically part of the device tag/descriptor.